About the empirical data question. Currently the App calculates the the speed from when the ball gets hit 'till its landing location. plans are to calculate the initial serve speed in a near update using empirical data.

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I am interested in the program. However, the above statement has me a little concerned.

As others have noted, I am interested in the speed at impact only, not an average.

i am afraid that to make accurate measure of ball speed, using simple camera from you iphone, is not gonna get you the results. You could get some results but it will be way off.

However i believe that using some kind of sensor inserted in the ball, and gps, you can get much better results. But its also a harder to do it right.

To the OP, i know that idea is good, but how would you create the app? I need details. How the app will know where is the ball in that video. How the app will know when the ball is going off the racquet, and when it crosses the net (to calculate)?

As a programmer myself, i would like to know your idea, or it didnt happened.

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I have a nice chronometer watch that times at .20 seconds.

I just need to find a way to serve a tennis ball that travels for 1 mile. Once I do, I'll be all set in calculating my service speed.

All you need is a good camera for someone to record your serve to find out how many frames it took from ball hitting to ball landing, and then plug the number of frames into the chart I provided above.

hey guys,
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The reference to the 500 up-votes (actually 750, wrote the text when it was still 500) might have been slightly misleading. It was not my intention and changed it to “The idea for this App originated from the Tennis Warehouse Community where more than 750 people up voted for this App to be made.”

As i said, the accuracy is definitely the best out there, ..........................

The first question I asked him was whether the app calculates an average speed. He said that the current version is only calculating the average speed, which is not good. Assuming that the difference between the initial speed and speed at landing is about 27%, the average speed due to air resistance should be about 16-17% off the initial speed. So, he is risking getting bad reviews due to "inaccurate" serve speed.

The second question I asked him was whether the app is doing 60 fps or 30 fps for my Iphone 4S. He said he programmed the phone to use 60 fps, rather than its default 30 fps rate. This means the resolution should be plus or minus about 5 mph (different between two adjacent frames) at high speed (i.e., over 110 mph).

My conclusion: His use of 60 fps is really great, but until the app calculates the initial serve speed, it's not ready for purchase IMO.

If you want to purchase the app, I think you should use the app for counting the frames and use the chart (see link below) to convert it to the initial speed.

The first question I asked him was whether the app calculates an average speed. He said that the current version is only calculating the average speed, which is not good. Assuming that the difference between the initial speed and speed at landing is about 27%, the average speed due to air resistance should be about 16-17% off the initial speed. So, he is risking getting bad reviews due to "inaccurate" serve speed.

The second question I asked him was whether the app is doing 60 fps or 30 fps for my Iphone 4S. He said he programmed the phone to use 60 fps, rather than its default 30 fps rate. This means the resolution should be plus or minus about 5 mph (different between two adjacent frames) at high speed (i.e., over 110 mph).

My conclusion: His use of 60 fps is really great, but until the app calculates the initial serve speed, it's not ready for purchase IMO.

If you want to purchase the app, I think you should use the app for counting the frames and use the chart (see link below) to convert it to the initial speed.

A few more days and version 1.2 will be available!
ServeSpeed version 1.2 is committed to the App Store! Just waiting for Apple to accept.

Most important updates:
- Uses algorithms to calculate your initial serve speed (ISS), which corresponds to the speed shown on TV (previous version only calculated the average speed).
- Calculates the speed at bounce and fall of the ball due to gravity.

I guess there was some confusion about if version 1.0 could already calculate the initial speed. Unfortunately this led to one guy leaving a bad comment in the App Store thinking he could serve harder than 56 miles per hour initial speed while the 56 miles per hour was in fact the average speed, so he did serve a lot harder. I would really appreciate it if some of you guys could mention this in another review in the App Store.

Quite some people asked for reviews, unfortunately not all the people who upvoted the App actually spend a few dollars on buying it.

Thanks to the dedicated player who wrote this in the Finnish App Store:
Kätevä ja toimii paremmin kuin odotin ★★★★

Via google translate I found that it means “Convenient and works better than I expected”!

I assure you, you wont regret your purchase. I would give a 60 day money back guarantee. But apple unfortunately doest offer this.

All I can ask is if you buy it please leave a review here and in the App Store.

In the mean time I’ll keep on working on the SOUND DETECTION functionality! So with a single click you can go the point of contact (racquet hitting the ball). Which will not only save lots of time but also improve the accuracy / human error because of the high sample rate.

The instruments i use for testing the accuracy are videos from the australian open where the professional radar gun shows the speed in the end. I currently only tested 9 videos and these are the test results:

The results are from ServeSpeed V1.2 (in a few days available in the App Store)

Some videos are harder to calculate than others depending on the frame right at the point of contact. This is why the slider bar in the app comes in handy. This way its possible to say that the serve is in between 2 frames (making it more precise). At the beginning this might be a bit difficult but once you get the hang of it, it becomes easier.

That's why i made an extra video explaining how to get the best precision (so you get all the ins and outs). If you sign up for the mailinglist (through the website or from within the app) you will receive it right away. Also i'll keep you updated on upcoming updates like the sound detection etc!

These are real test results, people can try it themselves.

PS: I am planning to test many more videos and based on these statistic try to improve the accuracy in upcoming updates.

You went to the Australian Open and recorded videos with an iphone? Then compared the iphone measurement to the displayed radar measurement?

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Yes!, all correct except for me not taking the videos, wish I could have been there (hopefully next year though!) . I got the videos through someone that I know.

Apple is taking its time :S , bit more patience and 1.2 should be there...

b.t.w. if people get a chance to records some more videos, you can always send them to me. I am planning on gathering more myself, but to more the better!
I guess I don’t necessarily have to mention this but if you do, make sure you record the moment the racquet hit the ball + its landing location and afterwards the speed that the professional radar gun will show.

I just checked out the new version's screen shots at the app store. Apparently, he is using the serve speed formula at http://www.donthireddy.us/tennis/speed.html which I told him about. The numbers all check out. This means the serve speed estimate should be very accurate.

The OP has finally turned the app into a useful tool by calculating the initial serve speed. I will be buying the app soon.

If you are just curious about your serve speed and are not interested in doing so on a regular basis, you can just record the serve and plug in the numbers into the website link above. That will do roughly the same thing with less accuracy.

The instruments i use for testing the accuracy are videos from the australian open where the professional radar gun shows the speed in the end. I currently only tested 9 videos and these are the test results:

The results are from ServeSpeed V1.2 (in a few days available in the App Store)

Some videos are harder to calculate than others depending on the frame right at the point of contact. This is why the slider bar in the app comes in handy. This way its possible to say that the serve is in between 2 frames (making it more precise). At the beginning this might be a bit difficult but once you get the hang of it, it becomes easier.

That's why i made an extra video explaining how to get the best precision (so you get all the ins and outs). If you sign up for the mailinglist (through the website or from within the app) you will receive it right away. Also i'll keep you updated on upcoming updates like the sound detection etc!

These are real test results, people can try it themselves.

PS: I am planning to test many more videos and based on these statistic try to improve the accuracy in upcoming updates.

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Does the application use both the frame at racket impact and the frame when the ball bounces to get the initial velocity? Or other information?

Hi, I just bought the app, after I have recorded the serve and press keep and calculate it just crashes! This is on the iPad.

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Hi ArthurX, great you bought the App! I have to admit that I haven’t tested the app on ipads, just iphones. On the iPhone everything works fine.
In the next update I’ll try to test it on the ipad and fix the error.

To your question about cricked. No this App is just for tennis! The distance measurements I do are for tenniscourts only.

Hi ArthurX, great you bought the App! I have to admit that I haven’t tested the app on ipads, just iphones. On the iPhone everything works fine.
In the next update I’ll try to test it on the ipad and fix the error.

To your question about cricked. No this App is just for tennis! The distance measurements I do are for tenniscourts only.

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I think the App on first startup asks for permission to your ‘Photo library’. This is only because it wants to save the recorded videos there. If you pressed [don’t allow] it might crash trying to access a video that was not saved to your library (i'll make sure i'll check that in the next version).

So if you did press [don’t allow] , you can simply solve this by going to your iphone ‘Settings’ -> ‘Privacy’ -> ‘Photo’s’ -> allow the ServeSpeed App here to use it.

Let me know if this solved your problem? If this was not the problem you might wanna update your ios version. I would very much like to hear from you !

I just checked out the new version's screen shots at the app store. Apparently, he is using the serve speed formula at http://www.donthireddy.us/tennis/speed.html which I told him about. The numbers all check out. This means the serve speed estimate should be very accurate.

The OP has finally turned the app into a useful tool by calculating the initial serve speed. I will be buying the app soon.

If you are just curious about your serve speed and are not interested in doing so on a regular basis, you can just record the serve and plug in the numbers into the website link above. That will do roughly the same thing with less accuracy.

Harry

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Thanks Harry! Yes I am using almost the same math as shown on that website.
It’s a great explanation if you wanna know more about how it’s calculated!

And yes you can calculate it all yourself but for 3 dollars really? It’s quite a lot of work to do it yourself. And if you’re like me you don’t wanna know it just once

Though I think the average speed of version 1.0 was very useful too for measuring improvements, ServeSpeed 1.2 of course is a lot cooler since with the initial speed you can compare yourself to the pro’s!

Great you are asking! i have looked into it already, though there are some struggles with android like the support for 60fps camera and so on. My first plans are to make the iPhone App even better with sound detection and some other great updates. So after that hopefully i can look into android.

Great you are asking! i have looked into it already, though there are some struggles with android like the support for 60fps camera and so on. My first plans are to make the iPhone App even better with sound detection and some other great updates. So after that hopefully i can look into android.

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I'll be looking forward to it, thanks for answering my question! In the mean time, I'm giving my buddy 3 bucks to buy it and we'll be testing it out this weekend.

Great you are asking! i have looked into it already, though there are some struggles with android like the support for 60fps camera and so on. My first plans are to make the iPhone App even better with sound detection and some other great updates. So after that hopefully i can look into android.

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In my opinion, I think you should do the Android version first as I don't think adding sound would be a substantial improvement. Even with sound detection, you would still have to review the video to select the frame showing the ball landing. Moreover, sound travels relatively slowly which means you need to ask how far the phone is from the server. In other words, you are not saving any steps in doing the calculation.

Even with only a 30 fps camera, the calculation would be reasonably accurate since you can select a point in between two frames.

I've been pretty excited to get an iPhone 5, first, because I just had bad luck with AT&T, and second, to get this app I've done these calculations with a digital camera many times. This app certainly makes it much MUCH easier.

One question I do have for the developer is, would recording someone serving on TV be a good way to test the accuracy of this app? It seems like the timing would be the same and you could easily determine the other needed data. This just seems like a good way to check against an actual speed gun at a tennis tourney.

98 mph flat first serve.
In 60 degree temps, Dunlop heavy balls, IN serves, should hit the backboard about just under 3' high, 21' behind the baseline on center serves.
Out wide, it can still go 100 if it barely hits the backwall after the initial IN bounce, because a wide serve travels up to 8' farther in distance.

98 mph flat first serve.
In 60 degree temps, Dunlop heavy balls, IN serves, should hit the backboard about just under 3' high, 21' behind the baseline on center serves.
Out wide, it can still go 100 if it barely hits the backwall after the initial IN bounce, because a wide serve travels up to 8' farther in distance.

You saw the vid of me serving when I was 62, couldn't run one step, first tennis day of the year, at night, in 60 degree heat.
The IN serves out wide, duece court, all hit about 24-36" high at the backfence. The camera was placed on a 48" tripod. Those weren't the best serves, just the first six I tried. Only TWO went IN.
If I served up the center, the bounce would be quite a bit higher, as you can see the ball dropping by the time it hit the backfencing on those wide serves.
I claim 100mph, which is about the fastest on rec courts at a 4.0 level of tennis.